Viscose or rayon pump



, Aug. 26, 1930. HAJEK 1,774,095

VISCOSB OR RAYON PUMP Filed July 5. 1928 F l E Patented Aug. 26, 1930 UNITED STATES PATENT OFFICE orro HAJEK, or VIENNA, AUSTRIA, ASSIGNOR- TO THE FIRM ALEX. FRIEDMANN, or

VIENNA, AUSTRIA VISCOSE 0R RAYON PUMP I Application filed July 5, 1928, Serial No. 290,650, and in Austria September 17, 1927.

This invention relates to viscose pumps for the spinning of viscose silk or rayon or similar liquids, which are liable to speedy solidification when in contact with air and especially to rayon or viscose pumps provided with an air vessel. Such air vessels are frequently employed in connection with pumps in general in order to equalize the fluid pressure in the pressure duct and to eliminate the various irregularities of pressure in said duct due to the reciprocating movement or to irregular working of the pump. They consist simply of a vessel of sufiicient volume, filled partly with air and partly with the liquid to be conveyed by the pump and in order to introduce said liquid a central feed pipe or tube is arranged, which projects into said vessel, While the liquid is carried off by a piping or tube leading from a convenient place near the bottom of the vessel.

Air vessels have also been employed in connection with rayon or viscose pumps fora similar object; but in this case the provision of an air vessel has very serious disadvantages. This is due to'the fact that the liquid is liable to solidification when in protracted or intimate contact with air and when thus incrustated is no longer fit for use and cannot be conveyed by a pump. If the usual construction with a central lead in pipe projecting into the air space of the vessel is adapted the liquid will come into immediate and intimate contact with the air when ejected from said pipe, with the result that it will be incrustated and solidified to a large extent. Moreover it will carry with it particles of air. a circumstance which has to be avoided as completely as possible, as any particle of air carried along with the spinning liquid will affect the process of spinning and the formation of a regular filament within the spinning nozzle.

To obviate these defects it would of course be possible to arrange the feed pipe of the air vessel at the bottom, so that it will always be covered with a suflicient layer of liquid. However with such an expedient the surface and upper layers of the liquid would be constantly kept at rest without appreciable movement of or change in its particles and these upper layers would therefore not take part inthe circulation. This leads again to solidification and incrustation of said upper layers, as the same particles of the liquid are in permanent contact with the air. Though this could be tolerated from the point of view of protection of the circulating liquid against the influence of the air, this will frustrate more or less the object of the air vessel itself which will not act as an equalizer of pressure, if the upper layer of the liquid has become solid.

It has also been proposed to use air vessels, in which liquid is admitted laterally at a point, which is arranged closely below the surface of the liquid. But also with construe tions of this kind the desired effect cannot beobtained. When the liquid is delivered at slow speed below the surface no permanent circulation of all particles of the surface leading from that surface to the exit opening of the air vessel'occurs and that circulation does not really include all particles; there will face, which therefore remains stagnant and will solidify.-

'My invention consists in a new and improved arrangement capable of obviating the various defect-s above mentioned. According to my invention the admission pipe for the liquid is arranged laterally near the wall of the air vessel and has a length so chosen that the orifice of the pipe projects up ,to a point which is located sufficiently near the surface but is somewhat below the average.

level of the liquid, the orifice of the pipe being thus always covered by a layer of liquid of suflicient thickness. The orifice of the admission pipe according to my invention has a restricted area of such a size that a relativel high speed of circulation is obtained, whic opening will at intervals not reach the surwill ensure a vivid and energetic circulation of allthe particles in the surface and also of the larger part of the body of the liquid without causing however the formation of foam. The exit opening of the air vessel is arranged atasuitable placebelow the orifice of theadmission pipe and near the bottom of the air vessel. By means of this Construction a circulation ofthe liquid is obtained, which also comprises and includes the superficial layer, inasmuch as the liquid projecting from the lateral feed pipe of the air vessel will not fall down after its exit but owing to its high speed is conducted by the wall at least partly to the surface thus creating a continuous circulation therein. No turbulent movement followed by mixture of air and liquid can occur as the liquid is always fed below the surface whatever the height of the level within the air vessel, while incrustation or solidification ofthe surface is prevented by the fact that the particles of this surface are in constant vivid circulation and are therefore only in contact with the air for a very short period of time.-

5 The mouth of the feed pipe is contracted or restricted to such a degree that the required speed of circulation of the particles is obtained.

A further advantage of my arrangement consists in the fact that the air vessel may be made of glass and that glass covers may be used, which may be easily manufactured and can be obtained on sale, so that my improved construction does not necessitate the introduction of new parts, which have to be manufactured separately.

The invention is illustrated by way of example in the accompanying drawing representing a longitudinal section through a rayon pump provided with an air vessel.

Inthe drawing P designates the rayon pump proper having a reciprocating plunger adapted to receive a to and fro movement from any appropriate driving mechanism.

Said pump is provided with the usual suction duct S through which the viscose or rayon is fed to the pump and with the pressure duct D, which" may or may not be provided with a non return valve V, shown in the form of a ball. Behind said valve the feed pipe R for the air vessel W is inserted. The air vessel W consists of a receptacle of sufficient size, made fluid tight in the usual manner and partly filled with liquid and partly with air. The feed pipe is arranged or bent in such a manner that its mouth occupies an eccentric osition within the air vessel and is in proximity to one of its walls. Said mouth may be contracted more or less in order to cause a circulation of the required .speed. The length of the feed pipe is such that the mouth is situated somewhat below the avera e height of the level E of the liquid in the air vessel.

ning liquid is making its exit into the duct Q,

In operation the liquid which is regularly fed to the air vessel by means of the pump P enters said vessel through the pipe R an by virtue of the position of the mouth of the pipe beneath the level of the liquid and by the lateral position of said pipe near the wall as well as on account ofthe arrangement of the exit opening or openings in the lower part of the air vessel is constrained to perform a regular circulating movement. The largest part of this circulation is confined to the interior of the liquid so that the circulating liquid does not come into contact with air at all and mixing with air or carrying along of air particles is thus effectively prevented. As however the mouth of the feed pipe R is on the other hand near the surface of the liq uid and also in close proximity to the wall which will prevent the jet .of liquid issuing from the mouth to fall immediately, the cir culating liquid will also reach the surface, and the particles of the surface will therefore also be included in the circulating stream of liquid. These particles of the surface will therefore change continuously and each particle is thus exposed to the air only during a very limited period of time, the surface being thus formed only by liquid particles continuously renewed by said circulation.

The movement of the liquid will be a very continuous and steady one and no turbulent movement will occur. Of course the speed of circulation may be chosen according to requirements by suitably choosing the cross sections of the pipes leading to and from said air vessel.

What I claim is:

In a pump for liquids liable to solidification or incrustation comprising an air vessel partly filled with liquid and partly with air and a feed pipe arranged below the average level of the liquid and eccentrically with respect to the axis of the air vessel and arranged at an angle thereto, a restricted orifice for said feed pipe, capable of acceleratin the liquid under pressure passing through that feed pipe and of imparting to the liquid issuing from said orifice .,a comparatively high speed that will cause v1v1d circulation of-the surface liquid and of the liquid body below and an exit opening for the-liquid arranged below that surface and below the orifice of the feed pipe.

In testimony whereof I aflix my signature.

OTTO HAJEK.

.At'the bottom of the air vessel an opening or port 0 is provided from which the spin- 

